Designed by Richard Harris the then Museum director(retired 01/01/11) as a long awaited replacement for a temporary poly-tunnel type structure that had been in place for nearly 15 years. The ‘white tent’ as it was known, was originally intended as an onsite timber frame restoration facility, the idea being that the public could watch the process of restoration whilst on a visit to the museum. The success of this idea let to the building of the Downland Gridshell and the white tent went on to serve in many other roles but mainly by the education department who used it as a wet weather space for school groups.

With this in mind, plus the intended re-organisation of the introductory exhibition in Hambrook barn, a space was devised whereby the floor area would be unobstructed by posts and have no windows in the walls to maximise display space. The roof pitch had to fit in with the surrounding exhibit buildings and so 45 degrees was decided on. With a span of 8 metres an 45 degree pitch would make the roof excessively high and obscure the view of exhibit buildings. A roof system was devised whereby use of 6 metre king post trusses would be placed accross the corners of the wall plates, the tie beams would take a cross beam and the cross beams would take two large LVL beams which would themselves form a box valley in the centre of the roof. The inside slope of the roof is covered in poly carbonate sheets and the exterior slope has a number of Velux conservation grade roof lights set into a traditionally tiled roof.

The insulation was from NBT and consisted of 200mm wood wool in the walls and 80mm rigid wood fibre sarking board accross rafters with scope to infill between rafters with 100mm wood wool. Anti racking was achieved using OSB on the interior face of the studs, this was pre-painted and edges lined with compriband to stop any drafts. All electrics are surface mounted with extra sockets high up to provide power for future exhibitions whilst being out of reach of the children. Heating is underfloor and powered by an air source heat pump.